4-Acetyl-2-hydroxy-2,5-dimethylfuran-3(2H)-one

Abstract

The facile synthesis of 4-acetyl-2-hydroxy-2,5-dimethylfuran-3(2H)-one (4) was achieved by the Mn(OAc) 3-mediated aerobic oxidation of 2,4-pentanedione or the direct reaction of Mn(acac) 3 in AcOH-TFE at room temperature under a dried air stream.

Facile Access to Highly-Substituted Dihydrofurans Using Resonated Vinylpentanedione Radicals Generated by Mn(III)-Based Oxidation

“…2 Especially, the reaction of pentane-2,4-dione was carried out under the Mn(III)-catalyzed aerobic oxidation conditions easily producing hydroxyfuranone via the predominant head-to-head radical coupling. 3 We then envisioned if the Mn(III)-enolate complex included a conjugate-available vinyl substituent, the produced radicals A during the single-electron transfer (SET) oxidation should resonate and might be stabilized, so that we could control the radical reaction (Scheme 1(b)). In order to prove the hypothesis, 3-(2,2-diphenylvinyl)pentane-2,4-dione (1a) was prepared 4 and underwent the Mn(III)-based oxidation that afforded the unexpected dihydrofuranyl acetate 3a from the 2° radical B' instead of the dihydrofuran hemiacetal 2a from the 3° radical B (Scheme 1(b)).…”